Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Water Usage
Rainwater Harvesting Calculator
Estimate how many litres of rainwater you can collect annually from your roof. Ideal for homeowners and gardeners planning rainwater tanks, irrigation systems, or off-grid water supply.
Fill in the required fields to see your result.
Water Usage
Household Water Bill Estimator
Estimate your monthly residential water bill from household size, an assumed per-person usage level, and the local volumetric water rate. A quick budgeting tool, not a substitute for reading your utility statement.
Fill in the required fields to see your result.
Key differences
| Rainwater Harvesting Calculator | Household Water Bill Estimator | |
|---|---|---|
| Category | Water Usage | Water Usage |
| Inputs required | 3 | 3 |
| Result | Annual Water Collection (cubic meters) | Monthly Water Bill ($) |
| What it does | Estimate how many litres of rainwater you can collect annually from your roof. Ideal for homeowners and gardeners planning rainwater tanks, irrigation systems, or off-grid water supply. | Estimate your monthly residential water bill from household size, an assumed per-person usage level, and the local volumetric water rate. A quick budgeting tool, not a substitute for reading your utility statement. |